This invention relates generally to synthesis gas, or syngas, coolers for use in a gasifier system, and, more specifically, to a quench ring assembly for use with a syngas cooler.
Many known gasifier systems include a reactor that defines a reaction chamber in which a fuel mixture is gasified to form a hot product gas and liquefied slag flows downward therefrom. A quench chamber holding a water bath is positioned in the reactor to receive and cool the hot produced effluent. A constricted throat that couples the reaction chamber with the quench chamber directs a stream of the effluent through a dip tube which defines a guide passage to conduct the effluent into the water bath. A toroidally-shaped quench ring is positioned radially inward of the dip tube to direct a water stream onto the dip tube's guide surface.
Most known quench rings include a high-wear hot face portion that is directly exposed to the gasifier's high-temperature and erosive conditions by virtue of the hot product gas which makes contact with hot face portion as the gas is channeled from the reaction chamber to the water bath. While the relatively cooler liquid flowing through the quench ring onto the dip tube's guide surface at least partially mitigates localized high temperatures, significant stresses and strains are induced in the hot face portion of the quench ring. Such thermally-induced stresses and strains facilitate increasing a replacement frequency of the hot face portion due to formation of cracks and fissures along the exposed surface. The hot face portion is typically a portion of a larger structural member, e.g., a removable/replaceable quench ring metal apron that facilitates providing the sacrificial wear surface. In addition, the apron is coupled to a plurality of cooling fluid inlet flanges, typically through welds, such flanges being aligned and coupled with fluid supply lines through fittings, e.g., Grayloc® fittings. Therefore, replacement and/or refurbishment of the hot face portion requires removing the gasifier from service, mobilizing a sizable maintenance crew, uncoupling the flanges, and removing the quench ring in its entirety in sections. During the replacement and/or refurbishment activities that occur outside of the gasifier, the hot face portion is repaired and/or replaced. However, upon replacement of the quench ring sections into the gasifier, the quench ring metal apron and flanges may not be in their original positions and orientations and may not align properly.